Driving assistance system

ABSTRACT

A driving assistance system includes a plurality of vehicles on which a plurality of microphones is mounted respectively and a server having an acquisition unit configured to acquire sound signals recorded by the microphones and position information of the vehicles. The server further has an estimation unit configured to estimate a position of one or more sound sources based on the sound signals and the position information and a providing unit configured to provide the estimated position of the one or more sound sources to the vehicles.

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2019-034671 filed onFeb. 27, 2019 including the specification, drawings and abstract isincorporated herein by reference in its entirety.

BACKGROUND 1. Technical Field

The disclosure relates to a driving assistance system.

2. Description of Related Art

In the related art, there is a known technique of collecting sounds witha plurality of microphones installed on the front, rear, right, and leftof a vehicle, obtaining a phase difference between sound signals, andestimating a distance between a sound source and a host vehicle and adirection of the sound source, for example, as described in thefollowing Japanese Unexamined Patent Application Publication No.2014-153927 (JP 2014-153927 A).

SUMMARY

However, a sound source that exists in a blind spot may not be capturedsince sound signals that can be collected by a single vehicle arelimited.

The disclosure provides a driving assistance system capable ofestimating a position of a sound source more accurately.

A first aspect of the disclosure relates to a driving assistance systemincluding a plurality of vehicles on which a plurality of microphones ismounted respectively, and a server having an acquisition unit configuredto acquire sound signals recorded by the microphones and positioninformation of the vehicles. The server further has an estimation unitconfigured to estimate a position of one or more sound sources based onthe sound signals and the position information and a providing unitconfigured to provide the estimated position of the one or more soundsources to the vehicles.

According to the aspect, it is possible to estimate the position of thesound source more accurately by estimating the position of the soundsource based on the sound signals recorded by the vehicles and theposition information of the vehicles.

In the above aspect, the acquisition unit may further acquire vehiclespeed information of the vehicles, and the estimation unit may estimaterelative speeds between the vehicles and the one or more sound sourcesbased on the sound signals, the position information, and the vehiclespeed information.

According to the aspect, it is possible to estimate the relative speedbetween the vehicle and the sound source in consideration of the Dopplereffect and thus to estimate a relative movement of the sound source withrespect to the vehicle.

In the above aspect, the server may further include a generation unitconfigured to generate a map of a surrounding environment where thevehicles travel based on the sound signals, the position information,and the position of the one or more sound sources.

According to the aspect, it is possible to provide information on theregion forming the blind spot of the vehicle and information on the roadsurface state to the driver by generating the map of the surroundingenvironment where the vehicles travel based on the sound signalsrecorded by the vehicles and the position information of the vehicles.

In the above aspect, the server may further include a slowing downcontroller configured to calculate a probability that any one of the oneor more sound sources approaches any one of the vehicles and slow downthe vehicle when the probability is equal to or larger than a thresholdvalue.

According to the aspect, it is possible to cause the vehicle to slowdown before a distance between the vehicle and the sound source becomesshort and thus to improve the safety.

In the above aspect, the slowing down controller may calculate theprobability based on at least one of the sound signals, the number ofvehicles under slowing down control among the vehicles, a history thatthe probability is equal to or larger than the threshold value,information on a date and time when the sound signals are acquired, andinformation on a surrounding environment where the vehicles travel.

According to the aspect, it is possible to calculate the probabilitythat the sound source approaches the vehicle more accurately.

According to the disclosure, it is possible to provide the drivingassistance system capable of estimating the position of the sound sourcemore accurately.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, advantages, and technical and industrial significance ofexemplary embodiments of the disclosure will be described below withreference to the accompanying drawings, in which like numerals denotelike elements, and wherein:

FIG. 1 is a diagram showing an outline of a driving assistance systemaccording to an embodiment of the disclosure;

FIG. 2 is a diagram showing a functional block of the driving assistancesystem according to the embodiment;

FIG. 3 is a diagram showing a physical configuration of a serveraccording to the embodiment; and

FIG. 4 is a flowchart of a process executed by the server according tothe embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the disclosure will be described with reference toaccompanying drawings. In each drawing, elements to which the samereference numeral is assigned have the same or similar configuration.

FIG. 1 is a diagram showing an outline of a driving assistance system100 according to the embodiment of the disclosure. The drivingassistance system 100 includes a server 10, a first vehicle 20, and asecond vehicle 30. A plurality of microphones is mounted respectively onthe first vehicle 20 and the second vehicle 30. The first vehicle 20 andthe second vehicle 30 may mount a sensor for measuring a position of ahost vehicle, for example, a global positioning system (GPS) receiver.The server 10 acquires sound signals recorded by the microphones mountedon the first vehicle 20 and the second vehicle 30 and positioninformation of the first vehicle 20 and the second vehicle 30 toestimate a position of one or more sound sources 50. In the exampleshown in FIG. 1, the sound source 50 is a bicycle. Although theembodiment will be described when the driving assistance system 100includes two vehicles, any number of vehicles included in the drivingassistance system 100 may be employed.

The bicycle that is the sound source 50 travels on a road with a forestENV1 on a left side and a residential area ENV2 on a right side, andapproaches a T-junction from a position which becomes a blind spot ofthe second vehicle 30 by being blocked by the residential area ENV2. Insuch a case, it is difficult to estimate the approach of the soundsource 50 with high accuracy solely by the sound signals recorded by themicrophones mounted on the second vehicle 30. The server 10 according tothe embodiment estimates the position of the sound source 50 based onthe sound signals of the sound source 50 recorded by the microphonesmounted on the first vehicle 20 through the forest ENV1 and the positioninformation of the first vehicle 20. The server 10 provides theestimated position of the sound source 50 to the first vehicle 20 andthe second vehicle 30. Accordingly, it is possible for a driver of thesecond vehicle 30 to know that the sound source 50 approaches from theblind spot and thus to travel safely.

As described above, with the driving assistance system 100 according tothe embodiment, the position of the sound source 50 is estimated basedon the sound signals recorded by a plurality of vehicles 20, 30 and theposition information of the vehicles 20, 30. Therefore, it is possibleto estimate the position of the sound source 50 more accurately.

FIG. 2 is a diagram showing a functional block of the driving assistancesystem 100 according to the embodiment. The driving assistance system100 includes the server 10, the first vehicle 20, and the second vehicle30. The server 10 includes an acquisition unit 11, a storage unit 12, anestimation unit 13, a providing unit 14, a generation unit 15, and aslowing down controller 16. The first vehicle 20 includes a firstmicrophone 21, a second microphone 22, and a third microphone 23. Thesecond vehicle 30 includes a first microphone 31 and a second microphone32.

The acquisition unit 11 acquires the sound signals recorded by themicrophones (first microphone 21, second microphone 22, third microphone23, first microphone 31, and second microphone 32) and the positioninformation of the vehicles (first vehicle 20 and second vehicle 30).The acquisition unit 11 may acquire the sound signals and the positioninformation from the first vehicle 20 and the second vehicle 30 througha wireless communication network. The acquisition unit 11 may furtheracquire vehicle speed information of the vehicles. The acquisition unit11 may store the sound signals, the position information, and thevehicle speed information in the storage unit 12 in association withacquired times.

The storage unit 12 stores sound signals, position information, andvehicle speed information acquired in the past. The storage unit 12 maystore information indicating a type of the sound source 50 inassociation with the sound signals, the position information, and thevehicle speed information.

The estimation unit 13 estimates the position of the one or more soundsources 50 based on the sound signals and position information of thevehicles. The estimation unit 13 may estimate the position of the one ormore sound sources 50 based on a disposition of the microphones mountedon the vehicle, intensity of the sound signal, and the positioninformation of the vehicle, and match the estimated position with theposition of the one or more sound sources 50 estimated from the vehicles20, 30 to improve estimation accuracy.

The estimation unit 13 may estimate relative speeds between the vehicles20, 30 and the one or the sound sources 50 based on the sound signals,the position information, and the vehicle speed information. With theaddition of the vehicle speed information, it is possible to estimatethe relative speeds between the vehicles 20, 30 and the sound source 50in consideration of the Doppler effect and thus to estimate a relativemovement of the sound source 50 with respect to the vehicles 20, 30.

The providing unit 14 provides the estimated position of the one or moresound sources 50 to the vehicles 20, 30. The providing unit 14 mayprovide the estimated position of the sound source 50 to the firstvehicle 20 and the second vehicle 30 through a wireless communicationnetwork. Accordingly, it is possible for the drivers of the vehicles 20,30 to confirm the position of the sound source 50 in the blind spot andthus to travel safely.

The generation unit 15 generates a map of a surrounding environmentwhere the vehicles 20, 30 travel based on the sound signals, theposition information, and the position of the one or more sound sources50. For example, the generation unit 15 may estimate that there is theforest ENV1 between the sound source 50 and the first vehicle 20 andthere is the residential area ENV2 between the sound source 50 and thesecond vehicles 30 from the fact that a transmission way of the soundgenerated from the sound source 50 differs between the first vehicle 20and the second vehicle 30 to generate the map. Further, the generationunit 15 may estimate a road surface state based on a change in the soundfrom the sound source 50 generated by a difference in the road surfacestate to generate the map. As described above, the map of thesurrounding environment where the vehicles 20, 30 travel is generatedbased on the sound signals recorded by the vehicles 20, 30 and theposition information of the vehicles 20, 30. Therefore, it is possibleto provide information on the region forming the blind spot of thevehicle and information on the road surface state to the driver.

The slowing down controller 16 calculates a probability that any one ofthe one or more sound sources 50 approaches any one of the vehicles 20,30 and slows down the vehicle when the probability is equal to or largerthan a threshold value. Here, when the probability that any one of theone or more sound sources 50 approaches any one of the vehicles 20, 30is equal to or larger than the threshold value, the storage unit 12 maystore information on a sound signal, position information, vehicle speedinformation, and date and time related to the event. For example, when aprobability that the sound source 50 approaches the second vehicle 30 iscalculated and the probability is equal to or larger than the thresholdvalue, the slowing down controller 16 may forcibly slow down the secondvehicle 30. Accordingly, it is possible to cause the vehicle to slowdown before a distance between the vehicle and the sound source becomesshort and thus to improve the safety.

The slowing down controller 16 may calculate the probability that thesound source 50 approaches the vehicle based on at least one of thesound signals, the number of vehicles under slowing down control amongthe vehicles 20, 30, a history that the probability that the soundsource 50 approaches the vehicle is equal to or larger than thethreshold, information on a date and time when the sound signals areacquired, and information on the surrounding environment where thevehicles 20, 30 travel. Accordingly, it is possible to calculate theprobability that the sound source approaches the vehicle moreaccurately.

FIG. 3 is a diagram showing a physical configuration of the server 10according to the embodiment. The server 10 includes a central processingunit (CPU) 10 a corresponding to a calculation unit, a random accessmemory (RAM) 10 b corresponding to a storage unit, a read only memory(ROM) 10 c corresponding to the storage unit, a communication unit 10 d,an input unit 10 e, and a display unit 10 f. Each of the configurationsis mutually connected so as to be able to transmit and receive datathrough a bus. In the example, the case where the server 10 isconfigured of one computer is described, but the server 10 may be formedby combining a plurality of computers. The configuration shown in FIG. 3is an example, and the server 10 may have a configuration other than theconfigurations or may not have some of the configurations.

The CPU 10 a is a controller that performs control related to theexecution of a program stored in the RAM 10 b or the ROM 10 c, andperforms calculation and processing of data. The CPU10 a is acalculation unit configured to execute a program (driving assistanceprogram) that estimates the position of the one or more sound sourcesbased on the sound signals and the position information which areacquired from the vehicles. The CPU 10 a receives various pieces of datafrom the input unit 10 e or the communication unit 10 d, and displays acalculation result of the data on the display unit 10 f or stores theresult in the RAM 10 b or the ROM 10 c.

The RAM 10 b is a storage unit configured to be able to rewrite data andmay be configured of, for example, a semiconductor storage element. TheRAM 10 b may store the program executed by the CPU 10 a and the piecesof data such as the sound signal, the position information, and thevehicle speed information. The above is an example, and the RAM 10 b maystore data other than the above or may not store some of the above.

The ROM 10 c is a storage unit configured to be able to read data andmay be configured of, for example, a semiconductor storage element. TheROM 10 c may store, for example, the driving assistance program or datathat is not rewritten.

The communication unit 10 d is an interface that connects the server 10to other apparatuses. The communication unit 10 d may be connected to acommunication network N such as the Internet.

The input unit 10 e receives a data input from a user and may include,for example, a keyboard and a touch panel.

The display unit 10 f visually displays the calculation result by theCPU 10 a and may be configured of, for example, a liquid crystal display(LCD). The display unit 10 f may display, for example, a map generatedby the generation unit 15.

The driving assistance program may be provided by being stored in acomputer-readable storage medium such as the RAM 10 b or the ROM 10 c ormay be provided through a communication network to be connected by thecommunication unit 10 d. In the server 10, the CPU 10 a executes thedriving assistance program to realize operations of the acquisition unit11, the estimation unit 13, the providing unit 14, the generation unit15, and the slowing down controller 16 described with reference to FIG.2. The physical configurations are examples and may not be requested tobe independent configurations. For example, the server 10 may include alarge-scale integration (LSI) in which the CPU 10 a and the RAM 10 b orthe ROM 10 c are integrated.

FIG. 4 is a flowchart of a process executed by the server 10 accordingto the embodiment. First, the server 10 acquires the sound signals, theposition information, and the vehicle speed information from thevehicles 20, 30 (S10). The server 10 estimates the position of the oneor more sound sources 50 based on the sound signals and the positioninformation (S11).

Further, the server 10 estimates the relative speeds between thevehicles 20, 30 and the one or the sound sources 50 based on the soundsignals, the position information, and the vehicle speed information(S12).

Thereafter, the server 10 generates the map of the surroundingenvironment where the vehicles 20, 30 travel based on the sound signals,the position information, and the position of the one or more soundsources 50 (S13).

The server 10 provides the position of the one or more sound sources 50,the relative speeds, and the map thereof to the vehicles 20, 30 (S14).

Further, the server 10 calculates the probability that any one of theone or more sound sources 50 approaches any one of the vehicles 20, 30(S15). Here, when the calculated probability is equal to or larger thanthe threshold value (YES in S16), the slowing down control is performedon a vehicle having an approaching probability of the sound source 50that is equal to or larger than the threshold value (S17). Thus, theprocess by the server 10 ends. The server 10 may repeat the aboveprocess.

The embodiments described above are intended to facilitate theunderstanding of the disclosure and are not intended to limit thedisclosure. Each component included in the embodiments and thedisposition, material, condition, shape, size, and the like thereof arenot limited to the above illustrated and can be changed as appropriate.Further, the configurations shown in different embodiments can bepartially replaced or combined with each other.

What is claimed is:
 1. A driving assistance system comprising: aplurality of vehicles on which a plurality of microphones are mountedrespectively; and a server including a processor, the processor beingconfigured to: acquire sound signals recorded by the plurality ofmicrophones in the plurality of vehicles and position information of theplurality of vehicles, estimate a position of one or more sound sourcesbased on the acquired sound signals and the acquired positioninformation, and transmit the estimated position of the one or moresound sources to the plurality of vehicles.
 2. The driving assistancesystem according to claim 1, wherein the processor is configured to:acquire vehicle speed information of the plurality of vehicles; andestimate relative speeds between the plurality of vehicles and the oneor more sound sources based on the acquired sound signals, the acquiredposition information, and the acquired vehicle speed information.
 3. Thedriving assistance system according to claim 1, wherein the processor isconfigured to generate a map of a surrounding environment where theplurality of vehicles travel based on the acquired sound signals, theacquired position information, and the estimated position of the one ormore sound sources.
 4. The driving assistance system according to claim1, wherein the server further has a slowing down controller configuredto (i) calculate a probability that any one of the one or more soundsources approaches any one of the plurality of vehicles, and (ii) slowdown the one vehicle when the calculated probability is equal to orlarger than a threshold value.
 5. The driving assistance systemaccording to claim 4, wherein the slowing down controller calculates theprobability based on at least one of the sound signals, a number ofvehicles under slowing down control among the plurality of vehicles, ahistory that the probability is equal to or larger than the thresholdvalue, information on a date and time when the sound signals areacquired, and information on a surrounding environment where theplurality of vehicles travel.
 6. The driving assistance system accordingto claim 1, wherein: the plurality of vehicles includes a first vehicleand a second vehicle; and the processor is configured to: estimate theposition of one or more sound sources based on sound signals recorded bythe first vehicle and position information of the first vehicle, andtransmit the estimated position of the one or more sound sources to thesecond vehicle.
 7. The driving assistance system according to claim 1,wherein the server includes a memory storing information indicating atype of each of the one or more sound sources.
 8. The driving assistancesystem according to claim 1, wherein the processor is configured tomatch the position of one or more sound sources estimated by the serverwith a position of the one or more sound sources estimated by theplurality of vehicles.